Sutter County, CA Accessory Structures: ADU Rules (2026)

H. Accessory Dwelling Units. Accessory dwelling units are subject to the following standards: 1. Accessory Dwelling Units are exempt from the General Plan land use density limitations and only one accessory dwelling unit is allowed per lot that shall also contain an existing single-family dwelling. 2. Accessory dwelling units shall not be sold separately from the existing dwelling unit located on the property but may be rented on a month-to-month basis. 3. For lots that are served by individual water (well) and sewer (septic) systems, the minimum lot size shall be as required by the Environmental Health Division. Both the primary and accessory dwelling unit shall comply with requirements of the Environmental Health Division for septic systems as those requirements exist at the time application is made. 4. Accessory dwelling units shall comply with same setback requirements as the primary dwelling unit on the parcel; however, no additional setback shall be required for an existing garage that is converted to an accessory dwelling unit, and a minimum setback of five feet from the side and rear lot lines shall be required for an accessory dwelling unit established above a garage 5. The Accessory dwelling unit shall be either attached to the existing dwelling or located within the living area of the existing dwelling or detached from the existing dwelling and located on the same lot as the existing dwelling. 6. The increased floor area of an attached accessory dwelling unit shall not exceed 50 percent of the existing living area, with a maximum increase in floor area of 1,200 square feet. 7. The total area of floor space for a detached accessory dwelling unit shall not exceed 1,200 square feet. 8. No passageway shall be required in conjunction with the construction of an accessory dwelling unit. 9. Accessory dwelling units shall comply with the same building and safety requirements as the primary dwelling unit and fire sprinklers are not required if they are not required for the primary dwelling located on the property. 10. The minimum rear yard setback to accommodate an accessory dwelling unit in the RAN, ER Districts shall be 20 feet and shall be 10 feet in the R-1 and R-2 Districts; however, at no time shall an accessory dwelling unit result in more than thirty percent (30%) rear yard coverage as measured using an average distance from the rear wall of the primary residence to the rear property line. 11. The maximum building coverage, specified in Table 1500-06-2, shall be 50 percent in the R-1 District to accommodate an accessory dwelling unit. 12. Parking requirements are not applicable to accessory dwelling units. 13. Attached accessory dwelling units are not considered new residential uses for the purposes of calculating local agency connection fees or capacity charges for utilities, including water and sewer service. 14. If an accessory dwelling unit proposed is the result of the conversion of existing space within an existing single family residence or accessory structure, it shall not be required to install new or separate utility connections directly between the accessory dwelling unit and the utility or impose a related connection fee or capacity charge. 15. For an accessory dwelling unit that is not described in subsection 13, the County may require a new or separate utility connection directly between the accessory dwelling unit and the utility and the connection may be subject to a connection fee or capacity charge that shall be proportionate to the burden of the proposed accessory dwelling unit based upon either its size or the number of its plumbing fixtures upon the water or sewer system. This fee shall not exceed the reasonable cost of providing this service.